Craniofacial Anomalies, Part 2 - Plastic Surgery Internal

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Le Fort II Osteotomy The Le Fort II osteotomy was popularized by Henderson and Jackson447 in cleft patients with associated paranasal and nasal shortening. Several variations have been described, including the tripartite osteotomy of Converse. 448 Le Fort III Osteotomy The mainstay of total maxillary advancement is the Le Fort III osteotomy. 421 The procedure can be combined with other osteotomies, specifically a Le Fort I, for definitive treatment of severe midfacial retrusion. 288 Interpositional bone grafts and a maxillomandibular fixation appliance373–377 are useful adjuncts. If decreasing the interorbital distance or widening of the palate is necessary, a facial bipartition is indicated (Fig 27). A long-term study by Bachmayer et al449 of maxillary growth after Le Fort III osteotomy in syndromic craniosynostosis showed minimal (mean 5%) vertical relapse with rigid stabilization of the midface, but severe anteroposterior growth retardation . Although the average forward movement of the maxilla at the time of surgery was 12.4mm, horizontal maxillary growth was minimal after surgery, and subsequent maxillary advancement was invariably required at the completion of growth. In a retrospective study of patients who underwent Le Fort III advancement for craniofacial dysostosis, Kaban and colleagues450 note early skeletal relapse in the sagittal plane in approximately 33% of patients. The magnitude of relapse was greater in SRPS Volume 10, Number 17, Part 2 patients with Apert syndrome than in those with Crouzon disease. The small amount of relapse during the first year was followed by progressive downward and forward movement of the midface until, 2 years after surgery, the midface was either anterior or inferior to the immediate postoperative position in 15 of 19 patients. Three patients required an additional Le Fort I osteotomy to correct Class III malocclusion. A prospective analysis of 12 “growing” patients by McCarthy and colleagues 451 disclosed a remarkable degree of postoperative skeletal stability. They followed this study with a clinical and cephalometric longitudinal analysis of 12 children with craniofacial synostosis syndromes who underwent Le Fort III advancement at age
SRPS Volume 10, Number 17, Part 2 morbidity and improve results include hypotensive anesthesia, shorter operative time, rigid stabilization of the mobilized bones at the end of the operation, fewer incisions, extensive antibiotic therapy, and greater surgeon’s experience. Munro and Sabatier 454 analyzed the results of craniofacial surgery in 1092 patients representing 2019 procedures. Complications of surgery accounted for 0.18% of deaths. Major complications occurred in 14.3% of patients but not all had permanent sequelae. Infection was the greatest problem, occurring in 5.3%. As the surgeons’ experience increased, the complication rate decreased. David 455 reviewed his 10-year experience with craniofacial surgery in Australia. The overall infection rate in 170 patients was 6.5%, with a marked age differential: 23.5% in adults and 2.2% in children. The highest infection rates were seen in patients who required tracheostomy and had longer operative times, and the most common pathogen was Pseudomonas. His recommendations to prevent infectious complications include operative intervention at an early age, short preoperative hospital stay, antibiotic prophylaxis to include gramnegative cover, isolating the dead space, and strict tracheostomy care. Poole 456 analyzed the postoperative course of 200 consecutive patients treated at the Oxford Craniofacial Unit. Their overall complication rate was 22%, including 1% mortality and 1% infections. In this series as well as in those mentioned above, the frequency of infection was greater in adults than in children and intracranial procedures carried a higher risk than extracranial procedures. Whitaker and colleagues 415 retrospectively analyzed the records of 164 patients with craniosynostosis operated on over a 12-year period. The authors state that excellent results can be expected in the asymmetrical deformities treated in infancy by a unilateral approach. Similarly, early surgery in the form of bilateral orbital advancement gives satisfactory results in most patients with mild symmetrical deformities. In contrast, cases of severe bilateral deformity or Apert syndrome often required a second, frequently extensive, operation. There were no deaths, blindness, or brain dysfunctions as a result of surgery. 42 DISTRACTION OSTEOGENESIS History Distraction osteogenesis (DO) is the process by which new bone is generated in the gap between two bone segments in response to the application of graduated tensile stress across the gap. DO was first described by Codivilla in 1905. 457 Beginning in the early 1950s, Ilizarov458 introduced the concept of distraction osteogenesis for acquired and congenital deformities of enchondral bone. 459 In 1973 Snyder460 reported distraction of the mandible in dogs, and 20 years later McCarthy et al57 described lengthening of the mandible in 4 patients with hemifacial microsomia by application of DO. In 1998 Molina and Ortiz-Monasterio published their series of mandibular distraction in 274 patients, 58 and the following year McCarthy reviewed his 10year experience with distraction of the mandible. 461 Habal462 reported midfacial distraction using an external distractor in 1995. That same year Polley463 described monobloc craniomaxillofacial distraction. Chin and Toth464 developed an internal device for midface advancement at the Le Fort III level in 1997. Biology of Distraction The process of distraction allows for the generation of bone—osteogenesis—as well as soft-tissue— histogenesis. In a gap between two bone segments initially a hematoma forms, which then develops into a soft callus. The application of tensile stress prevents progression to hard callus and subsequent fracture union. Instead, intramembranous bone formation occurs within the ever increasing gap. Within the bony gap there are three zones. The fibrous interzone intervenes between the two primary mineralizing fronts adjacent to the osteotomy. At cessation of distraction the mineralizing fronts meet and unite to create union during the consolidation phase. The resultant bony union is dependent on the latency, rate, rhythm, and consolidation period of the distraction process. Latency. Latency is the time period after osteotomy/corticotomy and before commencing distraction. In an ovine model Tavakoli et al 465 found no difference in mechanical strength or bone density of the callus when the latency period varied between
Page 2 and 3: CRANIOFACIAL EMBRYOLOGY To understa
Page 4 and 5: CENTRIC Corresponding Cranial Facia
Page 6 and 7: visceral arches, the intervening fi
Page 8 and 9: The Treacher Collins syndrome66 rep
Page 10 and 11: Fig 5. (Above) The nose and upper l
Page 12 and 13: Fig 8. Left, child with asymmetrica
Page 14 and 15: Fig 10. Cranial sutures in the huma
Page 16 and 17: Approximately 2% of cases of isolat
Page 18 and 19: tosis usually have normal mental de
Page 20 and 21: Fig 14. Technique for correction of
Page 22 and 23: SRPS Volume 10, Number 17, Part 2 F
Page 24 and 25: mutations implicated in the cranios
Page 26 and 27: Pfeiffer syndrome is inherited as a
Page 28 and 29: Associated Anomalies Although cervi
Page 30 and 31: • The transfacial approach330 may
Page 32 and 33: Relative indications for decompress
Page 34 and 35: traces the patients’ course over
Page 36 and 37: tomical correction of the deformiti
Page 38 and 39: TABLE 7 Brain Growth During the Fir
Page 40 and 41: Fig 24. Interocular distance measur
Page 44 and 45: 0 and 7 days. This would suggest th
Page 46 and 47: inconvenience to the patient and th
Page 48 and 49: SRPS Volume 10, Number 17, Part 2 F
Page 50 and 51: lengthening was 16.8mm in the mandi
Page 52 and 53: 1. Sperber GH: Craniofacial Embryol
Page 54 and 55: 85. Dufresne C: Treacher Collins Sy
Page 56 and 57: 169. Opperman LA, Chhabra A, Cho RW
Page 58 and 59: 247. Sutton LN, Barlett SP, Duhaine
Page 60 and 61: 334. Colen SR: Selective microvascu
Page 62 and 63: 420. Tessier P: Dysostoses cranio-f
Page 64: 503. Kunz C, Hammer B, Prein J: Man

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